Respected Monks,

I wanted to confirm if a variable delcared in a file is accessible and can be modified throughout the file, even inside a function, and that seems to be true.

pritesh@mintpad ~ $ more test_var_loc.pl 
use strict;
use warnings;

my $val = 10;
print "Outside the functions \$val is $val stored at ", \$val, "\n";
sub first {
    $val = 200;
    print "In the first function \$val is $val stored at ", \$val, "\n
+";

}
sub second {
    $val = 100;
    print "In the second function \$val is $val stored at ", \$val, "\
+n";
}
first();
print "After first function, before second function,  \$val is $val st
+ored at ", \$val, "\n";
second();
print "After second function,  \$val is $val stored at ", \$val, "\n";
pritesh@mintpad ~ $
[download]

The output is as expected.

pritesh@mintpad ~ $ perl test_var_loc.pl 
Outside the functions $val is 10 stored at SCALAR(0x1c307c8)
In the first function $val is 200 stored at SCALAR(0x1c307c8)
After first function, before second function,  $val is 200 stored at S
+CALAR(0x1c307c8)
In the second function $val is 100 stored at SCALAR(0x1c307c8)
After second function,  $val is 100 stored at SCALAR(0x1c307c8)
pritesh@mintpad ~ $
[download]

Now, what I don't get is, if within the function, I declare the $val as my $val (lexical scope), no warning message is shown. Nothing like "masking earlier declaration of $val". It just treats it as if it were a different variable.

pritesh@mintpad ~ $ more test_my_var_loc.pl 
use strict;
use warnings;

my $val = 10;
print "Outside the functions \$val is $val stored at ", \$val, "\n";
sub first {
    my $val = 200;
    print "In the first function \$val is $val stored at ", \$val, "\n
+";

}
sub second {
    my $val = 100;
    print "In the second function \$val is $val stored at ", \$val, "\
+n";
}
first();
print "After first function, before second function,  \$val is $val st
+ored at ", \$val, "\n";
second();
print "After second function,  \$val is $val stored at ", \$val, "\n";
[download]

The output is:

pritesh@mintpad ~ $ perl test_my_var_loc.pl 
Outside the functions $val is 10 stored at SCALAR(0xb2d7c8)
In the first function $val is 200 stored at SCALAR(0xb2d888)
After first function, before second function,  $val is 10 stored at SC
+ALAR(0xb2d7c8)
In the second function $val is 100 stored at SCALAR(0xb2e290)
After second function,  $val is 10 stored at SCALAR(0xb2d7c8)
pritesh@mintpad ~ $
[download]

I am confused. I thought that the second time I would get an error, but then it appears that, each my $var has scope limited to it's function or outside of the function. But if that's the case, I should have gotten an error the first time, stating "the variable requires explicit package name. Did you forget to declare my $var?" or something like that for the $val inside the function(s). I think I am missing something obvious here. Kindly help.

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